I don't think so, just exactly for the reason I gave above- dental schools don't know an undergrad's grading criteria and thus don't know how hard a student had to work for an A+. Did they just have to get 95+? Did they have to get 97+? Did they have to do extra credit/bonus to get 100+?
I don't think they really care too much about A+s....the whole change was due to large differences in GPA, I would think. The playing field was not level with some people getting a 4.3 because their undergrad awarded A+s, and some people only getting a 4.0 because their undergrad didn't award A+s. Granted, the playing field is still not level with differences in difficulty between different undergrads, but that's where the DAT comes in.